i have also had this issue, but it was from water getting to the starter, all was needed was the starter shaft to be greased and the fact that i had a loose battery wire sometimes did it this summer which is a pain in the a** in a 91 where you have to take the back seat out to access it.

I have been putting off working on the starter. I was at the lake again this past weekend. I thought I would tinker with it. I noticed that when I was putting the screw driver across the terminals at the starter, I was not by passing the solenoid. when I did put the screw driver across the 2 terminals that bypassed the solenoid, the starter turned over every time. I guess this means it is the solenoid. Can I replace the solenoid without removing the starter? I attached a pic, but it is not very good. Hard to see which starter I have. My engine is a Mastercraft vortec engine.
thanks for any help

does it get worse when it warms up? I had an issue where I replace the battery cable terminal ends and solved starting issues. My ends didn't even look bad. Clipped old terminals, installed new ones, and then coated with corrosion resistant.

Sorry Greg. I donīt figured out now because the boat stays in a winter hangar bit far away. But i think Hunterb has better technical understanding a few posts about. If you also have a 2012er with starting problems my dealer will give me more information about the solution. It is apparently a common problem for 2012. I will post when i get them.

Greg -
That appears to be non-serviceable.
Note that on the end of the case with the electrical connections, the metal part of the body is bent inwards to hold the piece with the electrical connections in-place. You could use a screwdriver to bend that lip back outwards (making a really ugly mess of it), pull it apart and replace bits and pieces, put it back together and use a punch to bend the lip back into place (no, really, I've never done anything like that in my life ), but the probability of success and reliability of the result aren't worth it. Besides, the solenoid is sealed to avoid having sparks ignite any gas vapors in your bilge, and doing this would break the seal. Can you say bad day at the lake? I knew you could...

I think it's time to get a new one. It should be a readily available part.